Publications by authors named "DaeSung Park"

The separation of diffraction effects from phase contrast is a major challenge for differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). The application of electron beam precession has previously been proven successful in homogenizing the direct beam and improving the imaging of both long-range electric and magnetic fields. However, magnetic STEM-DPC imaging performed in a low magnification (LM) STEM mode suffers from significant aberrations of the probe forming lens and the consequent impediment of small precession angles.

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Unlabelled: Recent advances in fabricating scalable two-dimensional or freestanding functional materials have shown promise for their use in modern silicon-based electronics and future technologies. A growing interest is in creating freestanding complex oxide membranes using new methods like epitaxial lift-off and mechanical exfoliation to enhance their quality and integrity. Despite these advances, it remains challenging to consistently produce high-quality freestanding oxide membranes on a large scale for practical use.

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Metallic nanoparticle dimers have been used to enhance the excitation rate of single-quantum emitters. The interparticle distance (d) of the dimers has a crucial influence on the signal enhancement. Therefore, precise control of d is desired for optimal performance.

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DNA origami is a flexible platform for the precise organization of nano-objects, enabling numerous applications from biomedicine to nano-photonics. Its huge potential stems from its high flexibility that allows customized structures to meet specific requirements. The ability to generate diverse final structures from a common base by folding significantly enhances design variety and is regularly occurring in liquid.

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In this study, we conducted a survey targeting 191 physical therapists (PTs) and 159 occupational therapists (OTs) in South Korea to explore attitudes toward virtual rehabilitation. Utilizing the Korean version of the ADOPT VR by Glegg et al., OT exhibited significantly more experience with virtual reality (VR) and active video games (AVG) than PT.

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Advanced in situ analyses are indispensable for comprehending the catalyst aging mechanisms of Pt-based PEM fuel cell cathode materials, particularly during accelerated stress tests (ASTs). In this study, a combination of in situ small-angle and wide-angle X-ray scattering (SAXS & WAXS) techniques were employed to establish correlations between structural parameters (crystal phase, quantity, and size) of a highly active skeleton-PtCo (sk-PtCo) catalyst and their degradation cycles within the potential range of the start-up/shut-down (SUSD) conditions. Despite the complex case of the sk-PtCo catalyst comprising two distinct fcc alloy phases, our complementary techniques enabled in situ monitoring of structural changes in each crystal phase in detail.

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Sound waves generate acoustic resonance energy that penetrates deeply and safely into body areas normal mechanical vibrations cannot reach. The sonic balance pad utilizes these sound waves to create an optimal musculoskeletal response. The purpose of this study was to investigate the effects of a 4-week ankle stabilization exercise program using a sonic balance pad on proprioceptive sense and balance ability in individuals with ankle instability.

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The size of nanoparticles is a critical parameter with regard to their performance. Therefore, precise measurement of the size distribution is often required. While electron microscopy (EM) is a useful tool to image large numbers of particles at once, manual analysis of individual particles in EM images is a time-consuming and labor-intensive task.

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This study explores important parameters for achieving a high-level positional control of DNA-nanoparticle hybrid structures by drop-casting onto a pre-structured silicon surface, in which the active adsorption sites were defined using electron beam lithography. By confining the adsorption sites to the scale of the DNA origami, we create multi-dimensional patterns and study the effect of diffusion and hybrid nanostructure concentration in the liquid on site occupation. We also propose a physical diffusion model that highlights the importance of surface diffusion in facilitating the adsorption of hybrid nanostructure onto active sites, particularly for two and one-dimensional adsorption sites.

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Conventional antiferroelectric materials with atomic-scale anti-aligned dipoles undergo a transition to a ferroelectric (FE) phase under strong electric fields. The moiré superlattice formed in the twisted stacks of van der Waals crystals exhibits polar domains alternating in moiré length with anti-aligned dipoles. In this moiré domain antiferroelectic (MDAF) arrangement, the distribution of electric dipoles is distinguished from that of two-dimensional FEs, suggesting dissimilar domain dynamics.

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Complex oxide heterointerfaces contain a rich playground of novel physical properties and functionalities, which give rise to emerging technologies. Among designing and controlling the functional properties of complex oxide film heterostructures, vertically aligned nanostructure (VAN) films using a self-assembling bottom-up deposition method presents great promise in terms of structural flexibility and property tunability. Here, the bottom-up self-assembly is extended to a new approach using a mixture containing a 2Dlayer-by-layer film growth, followed by a 3D VAN film growth.

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The use of biodegradable materials for implants is a promising strategy to overcome known long-term clinical complications related to permanent implants. Ideally, biodegradable implants support the damaged tissue for a certain period and then degrade, while the physiological function of the surrounding tissue is restored. Although Mg-based alloys nearly ideally lend themselves to biodegradable implants, a few critical shortcomings promoted the development of alternative alloy systems.

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The attitude toward telerehabilitation (TR) among therapists (191 physical therapists and 159 occupational therapists) in Korea was surveyed. The survey consisted of 15 questions in the following 8 domains: awareness(AW), attitude (AT), perceived usefulness (PU), perceived behavioral control (PBC), self-efficacy (SE), facilitating conditions (FC), barriers (B), and behavioral intention (BI). Therapists with experience in TR responded with higher scores in all domains except B, regardless of their specialty.

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The purpose of this study was to apply deep and slow breathing to the elderly, who can be classified as potential dementia patients, to confirm changes in the cognitive functions of learning and memory. Forty-five elderly subjects were randomly and evenly divided into a rest group (RG), a before group (BG), and an after group (AG). Measurements of their cognitive abilities were obtained before testing (PT), 30 min after learning (STT), and 24 h after learning (LTT).

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Utilizing advanced transmission electron microscopy (TEM), the structure at the (110)-type twin boundary (TB) of Ce-doped GdFeO (C-GFO) has been investigated with picometer precision. Such a TB is promising to generate local ferroelectricity within a paraelectric system, while precise knowledge about its structure is still largely missing. In this work, a direct measurement of the cation off-centering with respect to the neighboring oxygen is enabled by integrated differential phase contrast (iDPC) imaging, and up to 30 pm Gd off-centering is highly localized at the TB.

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Electrostriction is a property of dielectric materials whereby an applied electric field induces a mechanical deformation proportional to the square of that field. The magnitude of the effect is usually minuscule (<10 m V for simple oxides). However, symmetry-breaking phenomena at the interfaces can offer an efficient strategy for the design of new properties.

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The purpose of this study was to investigate the effects of the deep and slow breathing (DSB) on the chain-reaction changes of stress stimulation at over time by measuring electroencephalogram (EEG) and heart rate variability (HRV). Twenty-six healthy subjects were divided into two different groups: control group (CG) and DSB group (DSBG). All subjects were exposed to a stress-stimulated environment with 80% exercise intensity.

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Background: The cut-off values of walking velocity and classification of functional mobility both have a role in clinical settings for assessing the walking function of stroke patients and setting rehabilitation goals and treatment plans.

Objective: The present study investigated whether the cut-off values of the modified Rivermead Mobility Index (mRMI) and walking velocity accurately differentiated the walking ability of stroke patients according to the modified Functional Ambulation Category (mFAC).

Methods: Eighty two chronic stroke patients were included in the study.

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The light control of nonvolatile nanoscale memories could represent a fundamental step toward novel optoelectronic devices with memory and logic functionalities. However, most of the proposed devices exhibit insufficient control in terms of the reversibility, data retention, photosensitivity, limited-photoactive area, and so forth. Here, in a proof-of-concept work, we demonstrate the use of the tip-enhanced bulk photovoltaic (BPV) effect to realize programmable nanoscopic writing of nonphotoactive electronic devices by light control.

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Background: Stroke weakens the respiratory muscles, which in turn may influence the trunk stability; it is unclear whether the progressive respiratory muscle training (RMT) is effective in improving the trunk stability. The aim of this study was to investigate the effects of progressive RMT with trunk stabilization exercise (TSE) on respiratory muscles thickness, respiratory muscle functions, and trunk stability in chronic stroke survivors.

Methods: This is a pilot randomized controlled trial.

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A surge in interest of oxide-based materials is testimony for their potential utility in a wide array of device applications and offers a fascinating landscape for tuning the functional properties through a variety of physical and chemical parameters. In particular, selective electronic/defect doping has been demonstrated to be vital in tailoring novel functionalities, not existing in the bulk host oxides. Here, an extraordinary interstitial doping effect is demonstrated centered around a light element, boron (B).

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Article Synopsis
  • Spiders, especially cribellate spiders, excel in fiber processing by creating nanofibers to catch prey, utilizing advanced movements of their spinnerets and a special comb-like structure called calamistrum.
  • Compared to their natural methods, human techniques for handling artificial nanofibers are still quite basic, highlighting the potential for biomimetics to innovate spinning technology.
  • The study focuses on the calamistrum structure of the spider Uloborus plumipes using advanced imaging techniques to enhance understanding of its role in nanofiber processing.
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Background: Although the Kinect gaming system (Microsoft Corp, Redmond, WA) has been shown to be of therapeutic benefit in rehabilitation, the applicability of Kinect-based virtual reality (VR) training to improve motor function following a stroke has not been investigated. This study aimed to investigate the effects of VR training, using the Xbox Kinect-based game system, on the motor recovery of patients with chronic hemiplegic stroke.

Methods: This was a randomized controlled trial.

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Physiochemical interactions which occur at the surfaces of oxide materials can significantly impair their performance in many device applications. As a result, surface passivation of oxide materials has been attempted via several deposition methods and with a number of different inert materials. Here, we demonstrate a novel approach to passivate the surface of a versatile semiconducting oxide, zinc oxide (ZnO), evoking a self-assembly methodology.

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Background: Children with cerebral palsy (CP) exhibit diverse gait patterns depending on their neurological deficits and musculoskeletal problems. The Adeli suit treatment (AST) has been proposed as an intensive exercise protocol in the management of CP.

Objectives: The aim of this study was to compare the effects of a 6-week programme of combined AST and neurodevelopment treatment (NDT) with those of NDT alone on Gross Motor Function Measure (GMFM), balance, and gait in children with CP.

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